| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 10 |
| 5 | 18 |
| 6 | 60 |
| 7 | 115 |
| 8 | 410 |
| 9 | 822 |
| 10 | 2996 |
| 11 | 6174 |
| 12 | 22980 |
| 13 | 48324 |
| 14 | 182328 |
| 15 | 389187 |
| 16 | 1484410 |
| 17 | 3205710 |
| 18 | 12329988 |
| 19 | 26876586 |
| 20 | 104080812 |
| 21 | 228606012 |
| 22 | 890262984 |
| 23 | 1967830254 |
| 24 | 7699472676 |
| 25 | 17110322908 |
| 26 | 67215426440 |
| 27 | 150058534620 |
| 28 | 591517612616 |
| 29 | 1325828841480 |
| 30 | 5241992235888 |
[1,1,2,3,10,18,60,115,410,822,2996,6174,22980, 48324,182328,389187,1484410,3205710,12329988, 26876586,104080812,228606012,890262984,1967830254, 7699472676,17110322908,67215426440,150058534620, 591517612616,1325828841480,5241992235888] |